This invention relates to a pleating machine for pleating cloth with mutually converging folds, in particular a machine operative to form converging folds in the cloth and defining "upright" flaps therein i.e. folds extending crosswise to the face of a cloth piece to be pleated.
Pleating machines have been developed in the past which, to produce pleated cloth as above, were equipped with an angularly oscillating entrainment arm adapted to impart cloth to be pleated with a step-like forward movement, and with a movable abutment wall whereat said arm would form flaps or pleats.
The abutment wall was, in fact, arranged to initially act as an anvil member for the cloth being pleated, at the forward travel limit of the entrainment arm, and then raised and shifted to allow the formed pleats to move toward guiding members for the pleated cloth.
This prior approach, while seemingly workable, has proved inadequate to provide pleated cloth of an acceptable quality. In fact, the upward movement of said walls tends to drag the pleated cloth therealong if the entrainment arm is held at a position close to the wall. In the opposite case, the position of the folded flap remains uncertain and the fold has inadequately defined edges. Furthermore, said wall, in returning to its starting position from above, may easily interfere with the flap just formed and squeeze it or at least contact it in a wrong position.
With very flabby fabrics, it has also been found that the entrainment arm is unable to displace such fabrics accurately in an angular direction; that portion of said fabrics which is not caught between the arm and abutment wall being more likely to follow a path of linear direct approach to the abutment wall than an arched path toward it.
Lastly, the various component members of such prior machines have complex constructions, and are not readily adaptable to meet changing requirements as regards the depth and inclination of the pleats.
For these reasons, pleated cloth formed with converging or so-called "soleil" folds, is mostly processed manually by inserting cloth portions between a pair of pleated cardboards, and then pressing said cardboards accordion-like and loading them into appropriate devices to set the cloth in its pleated condition by a heat treatment thereof.
However, is may be appreciated that such a technique is unsatifactory both time- and labor-wise, and that such empirical procedures are practically unacceptable where large volume production is involved.